Attitude responsive power control for combustion engines



May 25, 1954 H. T; SPARROW ATTITUDE RESPONSIVE POWER CONTROL FOR COMBUSTION ENGINES Original Filed April 3, 1946 3 She ets-Sheet 1 m OONJUGTOR -6'! lso I33 A RANGE 7H2? VARIABLE RANGE r/9 THROTTLE f P H K 2e ,5 28

PR PELLER +OPENS In 0 I6 27 |2| 12o THROTTLE U f 5; 3| 32 I 26 :2 3: EEO E |5 In n3 -|so u 23 J '3 ISBm 24 THROTTLE asss'r MOTOR GATE\ r34 1 3s AMPL'F'ER TO OUTLET INVENTOR. HUBERT. I SPARROW BY ATTORNEY.

May 25, 1954 I H. T. SPARROW 2,679,355

ATTITUDE RESPONSIVE POWER CONTROL FOR COMBUSTIQN ENGINES Original Filed April 3, 1946 I 3 Sheets-Sheet 2 PRO LLER eovEFINoR fIZI Q l6 3| I20 I GEAR a TRA'N AIR SPEED I CONTROLLER l I I24 I25 l9 IQs ENGINE SPEED PREssuRE m m g CONTROL LEVER MOVEMENT 5 RANeE -RANGE 2 RANGE 3 z MANIFOLD PRE- D vIcE RESPON- ssuRE SELECTION IvE TO ENGINE BY I EvER. PROP. PEED ADJUSTS ELLER GOVERNOR MANIFOLD PRES- INVENTOR- ADJUSTED BY SURE SELECTOR HUBERT 1: SPARROW LEVER LEVER ADJUSTS AIR SPEED BY ONTROLLER WHICH IN TURN ADJUSTS PROPELLER GOVERN- M 79% OR AND ENGINE SPEED. rrow):

y 25, 1954 H. T. SPARROW 2,679,365

ATTITUDE RESPONSIVE POWER CONTROL FOR COMBUSTION ENGINES Original Filed April 3, 1946 5 Sheets-Sheet 3 AIR STREAM INVENTOR. HUBERT T SPARROW STATIC PRESSURE By 6 22 MIQM ATTOHNEX Patented May 25, 1954 ATTITUDE RESPONSIVE POWER CONTROL FOR .CORIBUSTION ENGINES .Hubert '1. Sparrow,

Minneapolis, Minn., assignor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware Original application Ap 659,261. Divided and 2, 1950, Serial No. 177,2

7 Claims.

This invention relates to improvements in power control apparatus for combustion engines, particularly to control apparatus for the engines used in aircraft. The present application is a divisional application of my Letters Patent No. 2,551,979 for Coordinated Speed and Pressure Control Apparatus for a Combustion Engine, issued May 8, 1951.

The primary object of the invention is to provide for the pilot, or flight engineer, a single control member by which the speed and intake manifold pressure of a controlled combustion engine may be controlled in a certain and predetermined sequence and with the rate of change of both factors in accordance with the known optimum operating characteristics of the individual engine.

Aircraft engines are conventionally provided with turbine driven supercharging compressors, or turbo-superchargers as they are known, to provide a controllable supply of air under pressure for admixture with the fuel and admission to the intake manifold of the engine. To meet the changing conditions of atmospheric pressures encountered at different flight levels the rate of compression of the air is controlled by adjustment of a waste gate regulating the differential pressure of exhaust gases from the engine across the turbine, said gases being employed for operating the turbine in accordance with conventional practice. To regulate the effective intake manifold pressures the aforesaid waste gate is positioned as required while in addition the usual throttle is employed as a further control, the latter particularly where the boost afforded by supercharging is not required. The engine speed is determined by the setting of a variable pitch propeller controlled by a propeller governor,

Thus it is evident that the effective power output of the engine, being a result both of engine speed and the intake manifold pressure which determines the volume of the combustible mixture fed to the engine, is regulated by no less than three separate controls, namely, the throttle, waste gate and propeller speed governor. It is further to be understood that, for each type of engine, there is a known relative value of engine speed and intake manifold pressure under all conditions which, if maintained, will result in optimum power output and maximum efficiency from the propeller.

Having in mind these facts, it is a further and important object of my present invention to provide a single lever or single member control for .an aircraft engine by which enginespeedv and ril 3, 1946, vSerial No. glis application August 2 intake manifold pressures may be conveniently controlled and selected in accordance with the known varying relative values of each, to secure at all times the optimumefilciency from both engine and propeller, and this without requiring that the pilot calculate and adjust the various controlling factors independently.

A further object is to provide a control system of this nature wherein the throttle remains under control of the manual selector member at all times so that the pilot'may close the throttle and override the control system as a whole in an emergency. An auxiliary object in this connection is to provide a .throttle control mechanism wherein is embodied a floating member positioned in accordance with the manually selected position of the single control lever,.permitting thethrottle to be opened as the engine is first set in operation, but providing flexibility such that the control lever may be further moved in a throttle opening direction for controlling engine speed and waste gate position, while retaining mechanical connection with the throttle.

Still a further object is to provide a combustion engine power control which is effective to vary the power output of the engine whenever the attitude of the engine. is varied.

Still another object is to provide a control apparatus for a combustion engine having a regulating means for adjusting the flow of one of the components of an ignitable mixture flowing into the engine which will vary the rate of flow whenever an attitude responsive device indicates a deviation of the engine from a predetermined attitude.

Other objects and advantages of niy invention will become apparent from a consideration of the appended specification, claims, and drawings, in which:

Figure 1 illustrates diagrammatically a complete engine controlsystem embodying my invention;

Figure 2 is a similar showing of certain parts of the system but under different conditions of operation;

Figure 3 is a chart illustrating roughly the ef fectof engine speed and intake manifold pressure brought about by my control system and indicating the function of the single control member by which these factors. are controlled.

Figure 4 shows the subjectcontrol apparatus as it is associated with the engine whose power output is being controlled. the main components of Figure 1 beingshown in block diagram form in this Figure 4;

Figure 5 shows one possible way in which the airspeed control of the subject apparatus may be constructed.

Referring now more particularly to the Figures 1 and 4, I show therein a complete control system for positioning and controlling a throttle 5, a waste gate 6, and a propeller governor I, all of conventional form. The throttle 5 as usual controls the flow of air to and through a carburetor C to the engine E and regulates the volume or weight of the combustible mixture supplied to the engine. The waste gate 6 controls the fiow of exhaust gases flowing from the engine exhaust manifold EM to an outlet 8 and as the gate is progressively closed an increasing volume of the gases is directed through a duct or noz zle 6 to a turbine In to increase the speed thereof as will be evident. The governor I regulates the pitch of a variable pitch propeller II which is driven by the engine for the usual purposes, the governor acting to maintain the propeller speed for which it is set.

The turbine Ifl operates a, compressor or supercharger |2 which receives air at atmospheric pressure through an intake I3 and delivers the air under pressure through an outlet conduit I4 and intercooler 10 to the engine, under further control of the throttle 5. The compression ratio of the compressor I2 is determined by its speed and hence the waste gate 6 affords very precise control of the pressure of the air delivered by the compressor.

For controlling and positioning the throttle 5, waste gate 6, and propeller governor I, and accordingly controlling the engine speed and power, I provide an electro-mechanical system, shown in detail in Figure 1, embodying as a primary controller a. single lever or member I5 adapted, as here shown, to be moved over an arcuate member I6 by hand from the indicated low power or initial position through three ranges designated in the drawing as ranges I, 2, 3, toward a maximum power position. Referring to Figure 4, the lever I5 is shown operatively connected to the mechanical camming apparatus M which in turn is coordinating the adjustment of the propeller governor 1 through appropriate connecting means H8, an air speed controller I22 through connecting means I24 and adjusting lever I23, the throttle 5 through connecting means 22, 26 and 21 and the electrical control circuits EC through connecting means I8. All of the connecting means have been shown in dotted lines and the direction of the arrows on the dotted lines indicate the direction the control travels over the connecting means. Also adjusting the control circuits EC are control signals originating from a device VA responsive to the speed and acceleration of the turbine I connected to the control circuits EC by connecting means SC, a vertical gyroscope I96 connected to the control circuits by connecting means VG, and a propeller speed sensing device I26 connected to the control circuits by connecting means PS. A further control signal for the circuits EC is derived from the pressure on the intake manifold IM of the engine E through a pressure sensing duct 90. The output control from the electric control circuits EC serves to position the waste gate 6 through connecting means 35 and the throttle through connecting means 32, 26, and 21. Reference should be made to Figure 1 and the discussion that follows to understand the details of construction and functioning of the control apparatus. Referring again to Figure 1, movements of the control lever I5 obviously will oscillate a shaft I1 whereon it is supported, thus moving a pressure selector wiper I8, a disc I9, and a cam 20 and a cam 2| all of which are attached to said shaft.

In addition, the control lever I5 positions the throttle 5 through a linkage mechanism comprising a first link 22 pivoted at-one end at lever 23 to the lever, a second swinging link or lever 24 pivoted at one end at 25 to the other end of link 22, and a third link 26 pivoted at 21a to the other end of link 24, the remaining end of the third link 26 being pivotally attached to the usual crank 21 for swinging the throttle 5 in its induction system conduit 28. The swinging link 24 is, furthermore, fulcrummed at 29 upon one end of a floating bar or supporting link member which is axially shiftable in supports 3| by means of a pinion 32 engaging rack teeth 33 on the bar. The exact nature and purpose of this shiftable or floating support will be presently made clear.

The waste gate 6 is driven by a motor 34 through a gear train 35. The motor 34 is of the split phase type, being provided with a pair of field windings 36 and 31 which are spaced electrical degrees apart, and an armature 38. The field winding 31 is supplied with electrical energy from a secondary winding 39 of a transformer 40 having a primary winding 4| which is connected to a suitable source (not shown) of alternating current. The energizing circuit for the winding 31 may be traced from the right hand terminal of the transformer winding 39 through a conductor 42, a condenser 43, the field winding 31, and a conductor 44 to the left hand terminal of the secondary winding 39.

The flow of electrical energy to the motor field winding 36 is controlled by an electronic amplifier 45 to which the winding is connected by conductors 46 and 41. The amplifier 45 is powered from another secondary winding 48 on the transformer 40, to which the amplifier is connected through conductors 49 and 50.

The amplifier 45 is provided with a pair of input terminals 5| and 52 and operates to supply the field winding 36 of the motor with alternating current the phase of which depends upon the phase of an alternating current signal impressed across these input terminals 5| and 52. Any common form of amplifier in which the phase of the output voltage reverses with a reversal of the phase of the input voltage may be used. A suitable amplifier of this type is shown in Figure l of the copending application of Albert P. Upton, Serial No. 437,561, filed April 3, 1942, now Patent No. 2,423,534, issued July 8, 1947.

It will be evident that if the motor field winding 36 is supplied'with alternating current which leads the current in the other field winding 31 by ninety electrical degrees, the motor will rotate in one direction, whereas if the current in winding 36 lags the current in winding 31 by this amount, the motor will rotate in the opposite direction.

The phase of the signal applied to the amplifier input terminals 5| and 52 is determined by the electrical conditions existing in a compound network which consists of five networks connected in series. Of these five networks, designated generally at 53, 54, 55, 56 and 51, the latter may be connected in, or eliminated from the series circuit by means of a single pole, double throw switch 58 having a center blade terminal 59 and spaced blade terminals 60 and GI. For convenience this switch will be considered first as so positioned that the network 51 is cut out of circuit,

reases the circuit being completed through-the switch blade' between the terminals 59'and-60 as seen in Figure 1. Bearing'this in mind, the-circuit may be'traced from the amplifier input terminal 5! through a conductor 62, the network 53, a conductor 63, the network '54, a conductor 64, the network 55, a conductor- 95, the network 56, a conductor 6'6, the-switch'58, and a conductor 57 back to the other amplifier input terminal 52.

"The network 56 includes a transformer secondary winding 68 across whose terminals are connected two series potentiometer or slidewire res'istances 69 and Why means of conductors II and 12. The transformer carrying secondary winding 68 is shown as having'a primary winding 268. The resistance 69, connected at one end by conductor II to the right hand terminalof winding 68, has also a conductive portion 13 which is connected by a conductor 14 to oneend of the resistance 'IILthe other end of which is connected by aforesaid conductor 12 to the left hand terminal of winding '68. Said conductor 14 is also connected to a center tap I5 on winding 68. Cooperating with the resistance 69 and its conductive portion 13 is the wiper I8 operated by the control lever I5 and the advance movement of said lever is seen to cause this wiper I8 to traverse first the resistance 69 and then the conductive'portion 13. The wiper thus varies in potential, with respect to winding 98, while traveling the resistance 59but maintains a fixed potential, dependent upon the magnitude of the whole of this resistance:69, while traversing the length of the conductive portion 13. In practice the slider I8traverses the whole length of the resistance 69 while the control lever I5 moves through range I, previously referred to, and travels along conductive portion I3 while the lever moves through ranges 2 and 3.

Cooperating with the resistance II! is a wiper 76 which is positioned by apropeller speed responsive controller I26 as will be discussed later. Thiswiper I5 is connected in circuit during the third or'final range of advance movement of the control lever I5 by means of a snap acting changeover switch shown schematically as comprisinga swinging blade TI to which conductor 66 is connected, and a pair of opposed contacts I8 and 19. Contact 18, into engagement with which the blade 11 normally is urged by. a biasing spring 11a, is connected by a conductor 89 to the wiper I8 and thus the circuit is normally completed to the network 56 through this wiper. Contact 19, on the other hand, is connected through a conductor 8i to the wiper It and the changeover switch is so located with respect to the disk I9 on the control lever shaft I? that a finger 82 thereon will engage the switch blade 11 .and oscillate it into engagement with contact 19 immediately as the control lever I5 enters its third or final range 3 of advance movement. Either the switch blade 19 is made resilient or some strain release means is provided to permit continued movement of lever I5 through range 3 after engagement of blade Ti with contact 19. Thus, during this range the slider I6 will control the potential produced by network 56 independently of control lever adjustment. As the lever is pulled back, the changeover switch will resume its normal position here shown by reason of the biasing action of spring 71a and manual control will be resumed by the slider I8.

Another slidewire resistance 83 is connected across one half of the winding by a connection 6o at'its ends between the conductors "II and "-14, leading respectivelyto the right hand terminal and center tap of this "winding. A slider 84 cooperates with this resistance 83 and together therewith forms a calibrating potentiometer 85. The connection between the center 'tap 150f the winding and the junction of the primary and secondary pressure selector controller'p'otentiometer formed, respectively, by the slider I8 and resistance 69 and by the slider -I6 and resistance I0, reduces the impedance between these sliders and slider'84-but does not-otherwise affect operation of the network.

The network 55 comprises a-transformer' secondary winding 86 across'the terminals of which is connected a slidewire resistance 81 as clearly shown. This transformer also has a primary winding 285. Cooperating with resistance t8'lis a slider 88 and together these :elements :comprise a pressure controller potentiometer 9'! which is adjusted in accordance with the pressure of the air deliveredito the engine. For this purpose a bellows 89 is connected by a pressureline 99 to some point in the induction system between the compressor I2 and the engine, preferably the intake manifold of the engine (as indicated by a legend in the drawing), so that this. bellows senses intake manifold pressure. An evacuated bellows 9| is providedand the tWOIbCllOWS are supported with their free ends .at 'oppositeisides of, and connected to, .thexslider '88 so "that the same is positioned along resistance 81 by :pressure changes. The bellows 9| compensatesthis controller for atmospheric changes in a well known manner. The conductor 65 connects sliders 84 and 88.

A second slidewire resistance 92 is connected as shown across the transformer secondary winding 86 and cooperating with this resistance is a slider 93 whichis positioned byxan acceleration responsive controller 194 connected to the turbine I9. Normally said slider 93 rests'upon a conductive spot 95 on resistance 92, so that minor accelerations will have no effect on the system, but the controller 94'operates toswing slider 93 across the resistance in response to over-acceleration oi the turbine. Said resistance 92 and slider 93 thuscooperate to form anacceleration limiting or compensating controller potentiometer 96.

The network54 comprises a secondary winding 98 on a transformer, having a primary winding 298, and a slidewire resistance 99 is connected by a conductor I99 to one terminal of winding 98 and by a conductor HJI to atap I92 on .the winding. A slider I03 cooperates with the resistance 99 and is positioned therealong by connection to a velocity responsive controller IM- which is driven by the turbine Il). The resistance 99 and a slider I93 together form a velocity limiting or compensating controller potentiometer I05 which is adjusted in accordance with turbine velocity, the controller lll loperating to move the slider across the resistance when the velocity exceeds a safe maximum value. The conductcr'M connects the sliders 93 and I03.

The network 54 also includes a slidewire resistance I95, theleft hand terminal of which is connected by a conductor I9! to the tap I92 on winding 98 and the right hand terminal of which is connected by a conductor I98 to the corresponding end terminal of the winding 99. Cooperating with the resistance IDS is a slider I99 and together these elements form'a'wastegate follow-up potentiometer EII O. The slider I09 is 7 moved along resistance I06 by connection to the aforesaid gear train 35 and the slider movement is thus concurrent with and proportional to that of the waste gate 6.

The network 53 comprises a secondary winding III on a transformer having a primary winding 3H and across the terminals of winding III is connected a slidewire resistance H2 by means of conductors H3 and H4. Cooperating with the resistance H2 is a manually movable slider H5 and together therewith the slider forms an overlap controller potentiometer H6, the purpose of which will later appear. The conductor 63 conheats the sliders I09 and H5, while conductor 62 leading to amplifier input terminal 5I is connected to one end of the secondary winding III.

The propeller governor I is adjusted directly by control lever I5 during the first range of advance movement thereof. For this purpose there is shown, for example, a crank II! on the governor I to which is connected a link I I8 operated by a follower H9 riding the cam 2 I. Said cam is so shaped that, during such first movement of the lever I5 and its shaft I1, the resulting oscillation of the cam will actuate the link H8 and swing crank II'I whereas continued movement of the cam will have no controlling effect upon the governor. For the remaining two ranges of movement of the control lever I5, the propeller governor I is adjusted by a reversible electric motor I through a gear train I2 I. Said motor is in turn controlled by an air speed controller I22 which, for example, is shown as regulated by a crank I23 to which is connected a link I24 having a follower I25 engaging cam 20. This cam 20 is then so formed that the initial movement of the cam, while control lever I5 moves through its first range, will have no effect on the air speed controller, while continued movement of the control lever through second and third ranges will adjust the air speed controller to select increasing air speeds. Such adjustment of controller I22 will then control motor I20 to adjust the propeller governor l and control the pitch of the propeller II as required. The propeller governor I may be of any conventional form.

The air speed controller may be of any conventional form such as is shown in Figure 5. The apparatus shown in Figure 5 is basically the same as that in the patent to Reichel, No. 2,363,143, issued November 21, 1944, with electrical contacts associated with the air speed indicating arm and with the adjusting screw acting as the airspeed selector. Referring to Figure 5, an air intake scoop is indicated at 225. This is exposed to the airstream along the forward line of flight of the craft. A conduit 226 is provided to supply a static air pressure to the subject controller. Located within the housing I22 is a bellows 221 which has the dynamic pressure from the air scoop 225 applied to the inside thereof and has the static pressure conduit 226 applied to the outside thereof. The bellows is resiliently supported by an adjustable blade 228, which is adjustable by adjusting means 229. The output arm of the bellows positions a floating lever 230 between a pair of contacts 23I and 232 associated with a three wire electrical control circuit. Movement of the adjusting mechanism toward the left has the efiect of increasing airspeed selected while movement toward the right has the effect of decreasing the airspeed selected. While an air scoop has been shown in Figure 5,

the conventional pitot tubes, as shown in the Reichel patent, may be substituted therefor.

It may here be noted, referring to Figure 1, that the first, second and third ranges of movement of control lever I5 are used merely for convenience in description and disclosure. Actually, of course, there will be no well defined or limited ranges of movement of the lever.

There is also provided a controller responsive to the engine or propeller speed, designated at I26, and which is driven, for example, by a tachometer connection to the propeller shaft. This controller, be it fly-ball governor type or otherwise, is arranged to position the slider 16 along the resistance 10 as the engine speed increases above a predetermined minimum. Inasmuch as the slider I6 and resistance 10 are cut into circuit only during the later advance movement of the control lever I5, the engine speed at which the controller I26 becomes efiective to shift the slider will necessarily be fairly high, and one corresponding to a desirable engine speed for the intake manifold pressure selected by the preliminary movements of the lever.

The pinion 32 hereinbefore described, for axially adjusting floating member 30 is actuated by a reversible electric motor I21 through a gear train I28. This motor I2'I is of the split phase type, like motor 34, and has a pair of field windings I29 and I30 spaced ninety electrical degrees apart, and an armature I3I. The field winding I29 is supplied with electrical energy from a secondary winding I32 of a transformer I33 having a primary I34. The energizing circuit for this field winding I29 may be traced from a lower terminal of secondary winding I32 through a conductor I35, a condenser I36, the winding I29 and a conductor I31 to the upper terminal of winding I32.

The fiow of electrical energy to the other field winding I30 is controlled by an electronic amplifier I38 to which said winding is connected by conductors I39 and I40. This amplifier is powered by another secondary winding I4I of transformer I33 to which winding the amplifier is connected by conductors I42 and I43. The amplifier I30 is provided with a pair of input terminals I44 and I45 and operates to supply motor field win ding I30 with alternating current the phase of which is determined by the phase of a signal potential applied across the terminals I44 and I45. The amplifier I38 thus operates to control the motor I21 exactly as the previously described amplifier 45 controls the waste gate motor 34 and no further description should be required at this point.

The input terminal I45 of the amplifier I38 is connected to the input terminal 52 of the amplifier 45 and for convenience in illustration such connection is shown as made by ground connections indicated at I46 and I41.

The signal potential applied to the amplifier I38 is determined in part by the compound series network previously described but in addition by a separate network I48 and a controller I49 forming part of the network 54. The energizing or signal input circuit for amplifier I38 may be traced from the terminal I44 through a conductor I50, the network I48, a conductor I5I, the controller I49 and network 54, the conductor 64, network 55, conductor 65, network 56, conductor 66, switch 58, conductor 61 and grounds I41 and I46 back to the other input terminal I45.

The network I48 comprises a transformer secondary winding I52 across the terminals of which denser I69. opposite direction as longas contacts I13 and I15 .are engaged. The energizing circuitifor winding I65, with-contacts I13'and I15 engaged, maybe 'traced from the ,upperzterminal of theinverter 19 is connected aslide-wire resistance I53 .bymeans of conductors I54 and I55. The transformer carrying winding I 52 has also a primary winding 352. Cooperating with the resistance 153 is a -:slider I56 positionedby areversible, throttle reset motor I51 through ageartrain I58. The resistance I53 and slider I56 together formathrottle reset controller controlling amplifier I38.

Thecontroller I46 comprises a slidewire resistance I 66 connected in parallelwith the follow-up resistance I06 by conductors I 6I and I62 and cooperating with said resistance is a slider I63. The slider 163 is operatively connected through aconnection I63a to the gear 32 so as to assume a position corresponding to that of throttlemotor I21. The resistance I66 and slider I 63 together forma rebalancing potentiometer or controller.

The motor I51 is of the split phase reversible induction type having a pairoffield windings I64 and I65 spaced ninety electrical degrees apart, andan armature I66. The field windings I64 and I65 :have a common terminal I61 connected to one terminal of an inverter I66, or other suitable source of alternating current electrical energy, and-between the other terminals of the windings is connected a condenser I69. Saidother terminals of the 'field windings I 64 and I65 are further connected byfiexible conductors I16 and Ill, respectively, to slider or chaser contacts I12 and I13. These'contacts'I12 and I113 arecarried in'spaced-relation upon an insulating base I14 aflixed to the link 26 of the throttle-adjusting linkage and are adapted upon opposite movements of saidlinkto make .selective contact with afixed center contact I15, to which the other terminal of the inverter I63 is connected bya conductor I16.

It will be evident that when the. link 26, ismoved to the right, in Figure 1, far enough to bring chaser contact I12 into engagement with center contact I115 a .circuit'willbe closed to'motor field winding I 64 which may be traced fromthe upper terminal of the inVerter IGB through the conductor I16, contacts I15 and I12, conductor I16,

through winding I64 .and through conductor I61 to the lower terminal of the inverter. This field winding I64 is thus energized directly by the inverter I68 and the voltage at the winding is of course in phase with thatat theinverter. At :the same time, the other motor field winding I65 is energized and the circuit may be traced from :the upper terminal of theinverter :168 through the conductor 516, the contacts I15 and.I12, the conductor I16, the condenser I69, the field winding I65, terminal I61 and back tothe lower xterininal of the inverter. The condenser'l69 is thus in circuit with'this winding I65 and the electrical eiiect thereof is to cause the voltage in this winding to lead that of the inverter, and the other field winding I64, by. one quarter cycle or ninety electrical degrees. As a result, the

motor armature I66 will rotate in one direction as long as the contacts I12 and I15 remain in engagement.

When the link 26 is shifted to the left in Figure 1 to a point bringing the chaser contact I13 into-engagement withcontact I15,the conditions .are reversed, the field winding I65 being now directly energized from the inverter I68 whilethe field winding I64 is energized through'the con- The motor will thus rotate ,in an I68 through the conductorJ16, contacts I15and I.13,.conductorI1I, winding I 65 an d terminal I61 to the lower terminal of the inverter. The, circuit for winding I64 may be similarly tracedfrom the upper terminal of the inverter throughconductor I16, contacts I15 and I13, conductor I1I, the condenser -I 69, winding I64, terminal I61, and back to the lower terminal of the inverter.

The operation of the motor I51, and its direction of rotation when operating, is-thus seen to be controlled by the position of the link 26 and thereby is determined by the position to which the throttle 5 is adjusted.

Operation Inthis description of the operation ofgmy system as shownin Figure 1, reference will alsobe had to Figures 2 and'3.

It will first be understoodthat all of the primary windings 4|, I8I, I34, 268, ,286, 298, SH, and 352 are connected to a common source of alternating current, or the various secondary windings are on a common transformer, ,so that the alternating potentials at the terminals of the secondary windings are in phase with each other. The signal potentials applied across the input terminals of the amplifiers and I38 are, of course, the algebraic sums of the potentials developed in the associated series networks.

Considering first the operation of the compound network controlling the waste gate amplifier 45, it will be noted that I have indicated the polarities of the networks 53, 54, and 56. Thus, the potential conditionsexisting during a half cycle when the polarities areas indicated will be described, for conveniencaand for arefverence potential the conductor 61, leading to amplifier input terminal 52 is shown as grounded at I41, or of zero potential.

With the-control lever I5 in minimum power position, as seen in Figure 1, the slider I8 is at the positive endof the resistance 69. On the other hand, the slider .84 is at an intermediate point along the resistance83 and so is at a negative potential with respect to the slider I8. .Since slider I8, leadstli, 66, and 61 areall grounded it will be seen that network 56 under these conditions introduces a potential into the series circuit connecting the input terminals of the amplifiers such that :the conductor is negative with respect to grounded conductor 61.

Turningnow to the network. 55, it will be seen that, with the sliders-88 and 93 in the positions shown, this network introduces into the series circuit a potential determined by the potential of slider88 relative to the potential of the left hand, positive terminal of the secondary winding '86. This potential is of apolarity such that the slider 93 is positive with respect to slider The positive potential thus developed in network 55 opposesthat produced in network '56 and the potential on conductor 64, with respect to grounded conductor v61 is the difierence of the potentials developed in the two networks thus far discussed. It will be assumed that the voltage introduced by network 56 is equal to that introduced by network 55 so that conductor 64 is at ground potential.

Considering next the network .54, it will be evident that with the sliders I63 and I09 in the positions shown they are at substantially the same potential with respect to each other, bein each directly in contact with the tap I 62 on secondary winding 68. For purposes of :this

discussion the network 54 may be considered as developing no potential in the series circuit and the conductor 63 is therefore at the same potential as grounded conductor 61.

Turning last to the network 83 it will be evident that with the slider H in the position shown, the conductor 62 is negative with respect to slider H5 and the conductor 63. The ma nitude of the negative potential thus introduced into the series circuit is determined by the position of the slider H5 along the resistance H2. Since conductor 63 is at ground potential, the conductor 62 is negative with respect to ground by the amount of the voltage introduced by network 53. Under such conditions the compound network is unbalanced and there is applied between the amplifier input terminals 5| and 52 a voltage such that terminal 5! is negative with respect to terminal 52.

The signal potential applied to the amplifier 45 under these conditions is of such polarity that the amplifier supplies energy to the waste gate motor winding 36 of such phase with respect to that supplied to winding 31 that the motor 34 attempts to drive the waste gate 6 towards open position. Since the waste gate 6 is already completely open, the motor simply exerts a torque against a limiting stop means (not shown).

Considering now the network conditions controlling the amplifier I38, it will first be understood that the input terminal I45 is grounded or at the same potential as conductor 61. Thus. conductor 64 is at the same potential as the grounded input terminal I45 assuming the balanced conditions in networks 56 and 55 are as discussed above. Tracing through networks 54 and I48, it is to be noted that rebalance slider I63 is at the extreme left hand end of resistor I60 so that no voltage exists between conductor 64 and slider I63. Hence, conductor I5I is likewise at ground potential. Referring now to the network I48, it is to be noted that slider I56 is in its extreme right hand position so that no voltage is introduced by network I48. Thus, conductor I50 leading to the input terminal I44 is at ground potential. Under these conditions, no voltage is supplied to the input terminal of the amplifier and the field winding I30 is deenergized. As a result, the motor I21 is deenergized.

For the present, the effect of the movement of the sliders 84, 93, I03 and H5 upon the amplifiers 45 and I38 will be ignored, particularly since these are essentially calibrating, or adjusting, and protective controls.

Assuming now that the engine is started up and the control lever I5 is advanced in range I of its movement, the slider I8 is moved away from the positive end of the resistance 69 having an immediate efiect on the potential conditions in the series circuits as they are controlled by the network 56. Still considering the operation under conditions whereat the polarities and potentials are those heretofore described, the effect of this movement of the slider I8 is seen to bea decrease in the negative potential at conductor 65 with respect to conductor 61. This results in a reduction in the negative voltage between terminals 5I and 52. Since the unbalance voltage is still of such a phase as to cause the waste gate to run towards open position and since the waste gate is already fully open, no movement of the waste gate takes place.

The aforesaid movement of the control lever I5 also is translated mechanically to an opening movement of the throttle 5, it being evident that 12 the endwise movement of the link 22 and resulting swinging movement of the link 24 about pivot 29 causes link 26 to shift to the left and open the throttle.

The rotation of the cam 2| by this movement of the control lever I5 also actuates the link H8 to adjust the propeller governor 1, causing the pitch of the blades of the propeller I I to be changed in such manner as to bring about a progressive increase in engine speed. The air speed controller I22 is not, however, adjusted during this portion of the movement of the control lever I5 as has been previously pointed out. While the movement of slider I8 over potentiometer 69 tends to make the conductor I50 and terminal I44 positive with respect to terminal I45, this effect is largely overcome by the increase in manifold pressure resulting from the opening of the throttle 5. This increase causes slider 88 to move to the left with respect to resistor 81 and hence to make conductor I50 negative with respect to ground. At low altitudes, the change in the effect of network 56 due to movement of the slider I8 and that in network 55 due to the movement of slider 88 as a result of the increase in manifold pressure may exactly balance each other. At higher altitudes, however, the manifold pressure will not rise enough for the signal introduced by the increase in manifold pressure to balance out the signal introduced by movement of slider I8. Hence, conductor I50 and terminal I44 become positive with respect to terminal I45. The phase of the signal applied to the amplifier under these conditions is such that a current is supplied to winding I30 of such phase as to cause motor I21 to drive link 30 to the left. Since the pivot point 25 is stationary, this causes movement of the link 26 to the left to cause an opening movement of throttle 5. At the same time, the slider I63 is moved by motor I21 to the right to cause slider I63 to become negative with respect to conductor IOI and hence to introduce a rebalancing voltage tending to make conductor I50 less positive with respect to ground. The opening movement of the throttle will increase the manifold pressure even more, reducing the unbalance voltage. When the motor I21 has moved to a position at which the rebalancing voltage introduced by bridge I49 is equal to the reduced unbalance voltage, the potential of input terminal I44 of amplifier I38 will again be the same as that of grounded terminal I45 so that the motor I21 stops its rotation. Any tendency of the manifold pressure to increase, assuming all other things to remain the same, will cause a movement of slider 88 to the left to cause the input terminal I44 of amplifier I38 to become negative with respect to the grounded terminal I45. This causes an opposite effect to that considered, namely operation of motor I21 in a direction to close the throttle.

As the lever I5 is moved to the right through range I, a point may be reached at which the throttle 5 becomes fully open, and further movement of lever I5 is temporarily prevented by a stop pin I10 engaging the throttle crank arm 21. The point at which lever I5 is stopped depends upon the position of throttle motor I21 which in turn is dependent upon the manifold pressure. When this happens, contact I15 engages chaser contact I13 to establish an energizing circuit to motor field windings I64 and I65, as previously traced. The direction of rotation under these conditions is such as to cause the motor I51 to move slider I56 to the left so as to cause conductor I to become negative with respect to conductor ISI. This causes conductor I50, and terminal I44. to be negative with respectto terminal I45. It will be recalled that the'effect of this type of unbalance is to cause the throttle motor to operate in such a direction as to close the throttle. As soon as the throttle starts moving towards closed position, however, the chaser contact I13 separates from contact I15 to inter rupt the circuit previously traced. The movement of the throttle motor I21 causes slider I63 to be moved back towards the left to increase the potential of conductor II in a positive direction and hence to rebalance the series of networks connected to amplifier I38 thus stopping further movement of the throttle in closing direction. With the throttle slightly closed, it is possible to move the lever I5 still further to the right. This causes reengagement of contacts I13 and I and the process just described is repeated. Thus, upon continuous pressure being applied to lever I5, the chaser contacts I 13 and I15 are continuously engaged with the throttle motor continually operating to shift the lever 24 to permit movement of lever I5 with the throttle in full open position. Thus, the effect of the throttle reset motor I51 is to permit a continued adjustment of lever I5 in throttle opening direction after the throttle has reached full open position. The reason for this is that the operation of the control system demands the movement of lever I5 throughout its entire range of movement despite the fact that under certain circumstances the throttle may be moved to full open position before the lever I5 has moved through range I of its movement. With this arrangement, the lever I5 is at all times mechanically connected to throttle 5 so that the throttle can at any time be manually moved to any desired position.

Whenever the pressure controller 91 is not satisfied by a movement of throttle 5 to a position approximating full open position, the waste gate motor 3 is placed into operation to start moving the waste gate towards closed position. It will be recalled that under the conditions previously described, the effect of bridges 53 and 56 in tending to make terminal 5I negative with respect to grounded terminal 52 was greater than the effect of bridge 55 in tending to make the terminal 51 positive with respect to terminal 52. As slider I8 is moved in a clockwise. direction, however, the negative voltage introduced between conduc tors 65 and 8!.) decreases. This is overcome to some extent by the movement of slider 88 towards the left as higher manifold pressures are maintained. As slider I8 is moved in a clockwise direction, however, a position is soon reached where the effect of bridges 53 and 56 just balances the effect of bridge 55. Let it be assumed that either the slider I8 is moved further or that the intake manifold pressure drops so as to cause the move ment of slider 38 towards the left. In either case, the effect is to cause conductor 52 and hence terminal 5! to become positive-with respect to terminal 52 instead of negative as has been pre viously the case. When this happens, the signal supplied to amplifier 35 is of such phase as to cause energization of motor 34 in a. direction to move the waste gate towards closed position. This is accompanied by a movement of slider I59 to the right so as to make slider I63 increasingly negative. The movement of waste gate 6 towards closed position continues until such time as the balancing effect resulting from the movementof rebalancing slider I09 to the right has been sufficient. to?v overcome the unbalanced. condition which initiated the movement of. the motor.

The effect of. moving waste gate 6 towards closed position is to result in exhaust gas being forced through the turbine IE] to initiate operation'of the supercharger I2. Thus, the pressure of the airsupplied to the intake manifold is in.- creased to satisfy the demand of the pressure controller. Thereafter, the waste gate will be. ad.-

.justed either towards open or towards closed position as is necessary to maintain the pressure at the selected value. Whenever a signal is supplied to the waste gate amplifier 45, a signal is also supplied to the throttle motor amplifier I38 since by reason of the arrangement including the throttle reset motor I51, the throttle motor amplifier network is kept constantly balanced. If the signal supplied to the two amplifiers is one calling for a higher manifold pressure, the throttle motor I21 will be operated in sucha manner as: to drive the throttle 5 towards open position. This will again bring contact I15 into engagement with contact I13, however, and cause energization'of the throttle reset motor I51 to move the slider I55 to the left. This signal tends to counteract the signal applied to amplifier I38. The throttle reset motor I51 continues to operate and continues to move slider I56 to the left until the change in voltage across the terminals of network I48 is greater than the unbalance voltage which initiated operation of motor I 21. When this happens, the throttle motor is operated in the opposite direction to move the contact I13 away from slider I15. Thus, despite the fact that the movement of th slider I5 or. the movement of the pressure controller slider 88 in a direction to: call for increased manifold pressure, causes operation of the throttle motoreven after the throttle is in wide open position, no harm is .done since the throttle reset motor merely operates to readjust the balance of the network until the throttle motor amplifier is no longer energized.

It is often desirable to start closing the waste gate some time before the throttle is fully open. In other words, it is desirable to have an overlap between the throttle and waste gate operations. Theoverlap controller H5 is provided for this purpose. As slider H5 is moved downwardly, the balance point of the series of networks controlling the energization of amplifier 45 is changed in such a manner as tocause waste gate 6 to be closed. at a higher manifold. pressure mat a less advanced position of slider I8 than would otherwise be-the case. It will be noted that the bridge 53 including the overlap controller II6 does not aifect the energization of the throttle motor amplifier I38. Thus, movement of slider- II5 causes th closing of waste gate 5 to take place earlier in the sequence than would otherwise be the case without affecting the operation of Thisresults in an increase the throttle controls. in the amount of overlap between the throttle and waste gate operations.

The calibrating potentiometer is provided for the purpose of adjusting the manifold pressure. It will be clear that the movement of the slider 84 to the right increases the manifold pressure that is maintained for any given setting of the slider I8. Similarly, amovement of the slider 84 to the left effects a decrease inthe value of the manifold pressure that is maintained by the system for any given setting of the slider I8.

The purpose of the acceleration controller isto cause the waste gate 5 to be moved towards open:

position whenever the acceleration of the turbine becomes excessive. Upon the acceleration exceeding a predetermined value, slider 96 is moved to the right. This tends to cause conductor 64 and hence terminal to become more negative with respect to grounded terminal 52. It will be recalled that the effect of making terminal 5I negative with respect to terminal 52 is to cause the waste gate to be moved towards open position. Similarly, if the velocity at any time becomes excessive, the slider I03 is moved toward the right. This in turn has a similar efiect causing terminal 5I to be made more negative with respect to terminal 52. The operation of the calibrated potentiometer 85, the acceleration controller and the velocity controller is more fully described in my co-pending application Serial No. 476,797 filed February 22, 1943, now Patent No. 2,477,668.

The operation which has been described so far is that which can take place While the operating lever I5 is in range I. Summarizing, during this range of movement of lever I5, the setting of the propeller governor is constantly increased to increase the speed of the propeller. Similarly, the

setting of the manifold pressure controls are increased to maintain a continually increased manifold pressure. The manifold pressure and propeller speed for any given setting of the lever I5 is maintained at values dependent upon the position of the lever. When the demand for manifold pressure is relatively low, this is taken care of by an opening movement of throttle 5. As the need for manifold pressure increases, however, the waste gate 6 is moved towards closed position to bring the compressor I2 into operation to an increasing extent. During this first range of movement, the air speed controller has not been adjusted so that it remains inactive.

Upon control lever entering range 2, the engine speed is adjusted in accordance with air speed, as selected by the air speed controller I22. The direct control over the propeller governor 1 by the control lever I5 ceases as the lever reaches range 2 of its movement, as has been pointed out, but the air speed controller I22 is then advanced by cam and link I24 to select a suitable air speed for cruising and like operations. In turn the controller I22, through motor I20 and gear train I2I, positions the propeller governor 1 to select an engine speed known to be best adapted to that air speed. These are factors determined by the particular engine and aircraft and the cam 20 is properly selected and formed in order to bring about the adjustment in a precise and predetermined manner.

The movement of the control lever I5 through the range 2 has no effect over the controlled intake manifold pressure since the slider I8 is then moving across the conductive dead spot 13 of potentiometer 69. Thus the balance conditions in the network controlling amplifier 45 are not affected by the movement of the lever and the waste gate 6 is controlled by the pressure controller 91 to maintain a constant manifold pressure. As the lever is advanced through range 2, the waste gate will be moved toward the open position because the increased R. P. M. will result in a greater boost from the engine driven blower.

As the control lever I5 now enters and advances through range 3 of its adjustment, the throttle resetting action continues as has been described, and the air speed controller I22 is advanced to increase engine speed further by its control over the propeller governor 1. At

this point, however, manual selection of the intake manifold pressure ceases as ,the changeover switch arm 11 is engaged by the finger 82 on disk l9 and swung into engagement with fixed contact 19. The circuit to the slider I8 is thus broken, and instead conductor 61 (and 55) is connected to the slider 16. Since slider I8 is at the potential of the left terminal of resistor 10 when this happens and since slider 16 is at the right end of resistor 10, no abrupt change in the manifold pressure occurs. As previously explained, the slider 16 is positioned by the controller I26 responsive to propeller 0r engine speed, and as the speed increases above a predetermined value, in response to the advance of the control lever I5, controller I26 moves slider 16 from the right hand end of resistance 10 along the resistance at a rate preselected to properly increase the intake manifold pressure along an optimum operating curve. The adjustment of slider 16, of course, selects and adjusts the pressure by unbalancing the networks controlling amplifiers 45 and I38 in such a manner as to operate either motor 34 or motor I21 to position either the waste gate 6 or the throttle as required.

In summation, it will be evident that advancing the single control lever I5 will result in an increase in engine speed and power at a certain rate and proportion predetermined and selected in accordance with known operating characteristics.

Basically, the control lever first increases intake manifold pressure and engine speed along a preselected desirable curve, following the known optimum line and then positions or sets an air speed controller which in turn instigates the selection of. engine power and speed to maintain the selected air speed regardless of altitude and other varying factors. All this is accomplished without requiring precise adjustments of several controls by the pilot, with the attendant possibility that optimum operating conditions would not always be maintained.

The effect of the movement of the control lever on engine speed and power is indicated in the chart of Figure 3 and the controls and adjustments responsive to the lever, as it moves through its three ranges, are set out with reference to the corresponding changes in engine speed and power. The engine speed and pressure curves as here shown are, of course, only approximate and in practice they will closely follow the optimum power curves as determined by propeller load curves, fuel economy, detonation limits, and other considerations.

- The return movement of the control lever I5 toward starting position will, of course, reverse the actions just described and will reduce both engine speed and intake manifold pressure. It will be understood that a resetting action of the throttle will occur during this movement, the chaser contact I12 engaging contact I15 to close the circuit between the inverter I68 and field winding I64 of the motor I51 in order to shift the slider I56 to the left and supply the amplifier I38 with a signal potential such as to run the floating link 30 back toward the left until the slider I56 finally reaches the right end of resistor I53.

As is well known in the art there is a pronounced tendency for the air speed of an aircraft to fall off as it makes a turn. Inasmuch as, during the latter portions of the advance movement of control lever I5, the selection of 17 intake manifold pressure and engine speed are instigated by the controller I 22 responsive to air speed, it is desirable that any factors materially aifecting air speed be overcome.

It is the function of the network 51 to overcome this undesirable effect and compensate the system thereagainst. To this end, the network 51 comprises a transformer having a secondary winding I88 and a primary winding ItI, and the latter is connected to the same source of energy as all the primaries of the other networks. A slidewire resistance I82 is provided and a center tap I83 thereon is connected to one terminal of the secondary winding I811 by a conductor I 8'5. The ends of the resistance I82 are connected to each other by conductors I85 and I86 and are further connected by a conductor I87 to the other end terminal of secondary winding I 36. A slider I83 cooperates with the resistance I82 and is connected by a conductor I39 to the lower terminal [H of the switch 555. The slider its is associated with a vertical gyroscope 896 (shown schematically) and is positioned with respect to resistance I82 in response to banking of the plane.

The slider I88 is operatively arranged to normally stand at the center of the resistance I82 (Figure 1) but is positioned by gyroscope I96 to move therealong away from such position in opposite directions in response to banking movement of the plane, or movements thereof about a longitudinal roll axis. This section is illustrated in Figure 2, and since such control operation, per se, is known it will not further be described herein.

Assuming now that the switch arm of switch 58 is manually operated to close the circuit between its terminals 59 and 6|, it will be evident that the network 5! is then included in circuit between the network 55 and the conductor 67 leading to amplifier input terminals 52 and M5. The circuit may be traced, from the conductor 85, making connection to network 56, through terminals 59 and 6! of the switch 58, conductor I89, the slider I88, center tap 583 of the resistance I 82, conductor its and. a conductor I9!) which connects the left hand end terminal of the trans former to conductor 67. Under normal conditions, it will be seen then that the network 5'! has no effect in the series circuit, since none of the resistance I82 is in circuit and direct connection is made between the slider I88 and the center tap I83.

However, as the plane banks or rolls, as it will on starting to turn to either side, the slider I88 will, as stated, swing in one direction or another placing a part of the resistance I82 in circuit, the amount depending on the magnitude of the movement of the plane about its roll axis. Assuming the potential conditions which exist during a half cycle at which the ends of the secondary winding I80 are of the polarity indicated, such movement of the slider I88, in either direction, will result in the slider I 88 becoming positive with respect toconductor I98. The network 51 under these conditions is thus seen to introduce a potential into the series circuit such that the amplifiers 45 and I38 are provided with signals tending to cause them to operate in such a manner as to increase the manifold pressure. If the throttle is entirely open, the eiTect of this will be to cause the motor 3 to move the waste gate towards closed position, from whatever position it may have been previously. If the throttle is not fully open, the effect will be to cause the throttle to move towards open position. In either event, the result is a boost in intake manifold pressure and engine power calculated to overcome the tendency toward the reduction in air speed as the aircrait turns. When the turn is completed, the slider I 88 returns to normal position, this manifold pressure increasing signal potential is removed, and the selected engine power condition is restored.

The switch 58 may be manually operated by the pilot or flight engineer to connect the network 51 into the overall control system whenever optimum flight characteristics are desired. It will be seen that with the network 51 switched into the power control circuit, when the craft goes into a turn, the roll axis controller "I 96 will anticipate the eiiects of the turn and increase the manifold pressure, and therefore the power, before the airspeed has changed. This anticipation correction will be present no matter in what range the power lever I5 may be adjusted.

Conclusion It will be apparent that in multi-engine installations of my control system, wherein a separate control lever I5 is provided for each engine, the speeds of the individual engines may be accurately synchronized, during the time the levers are in range 2 of their movement, by minor adjustments and without afiecting intake manifold pressures, optimum cruising conditions and trim may thus be readily attained. It will further be apparent that the control apparatus will modify connecting said controlling means to said motor means to modify the affect of said pressure selecting means whenever the craft departs from. said predetermined attitude.

2. Apparatus for controlling an aircraft combustion engine which drives an air moving device, comprising, a first controller responsive to the speed of said air moving device, a second controller responsive to the deviation of said craft from a predetermined attitude, a motor means arranged for regulating the power output of the engine, and means connecting said first and second controllers to said motor means to control the operation of the same.

3. In an aircraft engine power control apparatus, the combination comprising, airspeed responsive means for adjusting the engine power control apparatus to maintain a selected aircraft speed, and means responsive to movement of said aircraft engine about its roll axis connected to the power control apparatus for increasing power when there is a roll deviation from a normal position.

4. In an aircraft engine power control apparatus, the combination comprising, balanceable electrical network control means for maintaining a. selected manifold pressure, and aircraft attitude responsive means connected to such control means to vary the balance of said means in 19 an increased manifold pressure direction when said attitude responsive means indicates a deviation from a predetermined normal position.

5. In a control apparatus for an aircraft engine having a turbo-supercharger, the combination comprising, a controller adapted for regulating the effect of the turbo-supercharger on engine intake pressure, airspeed responsive means, means operably connecting said airspeed responsive means in controlling relation tosaid controller, and roll responsive means connected to said controller to increase the effect of the turbosupercharger when a roll condition exists.

6. Control apparatus for use with an aircraft combustion engine having a propeller pitch control device and a manifold to which air is controlled by a throttle, comprising, a manually operated control lever, manifold pressure respon sive means, engine speed sensing means, motor means for controlling said throttle, connection means including said pressure responsive means and said engine speed sensing means for connecting said lever in controlling relation to said motor means, air speed controlling means, connection means including said air speed controlling means for connecting said lever in controlling relation to said propeller pitch control device, attitude responsive means, and means operatively connecting said attitude responsive means to said motor means so that variations of the attitude of the aircraft are effective on the operation of the combustion engine.

7. Control apparatus for use with a combustion engine having variable loading and an intake chamber to which air is controlled by a flow control device, comprising, a control lever, intake chamber pressure responsive means, engine speed sensing means, actuating means for controlling said flow control device, connection means including said pressure responsive means and said speed sensing means for connecting said control lever in controlling relation to said actuating means, speed controlling means, connection means including said speed controlling means for connecting said lever in controlling relation to said variable loading means, attitude responsive means, and means operatively connecting said attitude responsive means to said motor means so that variations of the attitude of the combustion engine are effective on its operation.

References Cited in the file Of this patent UNITED STATES PATENTS Number Name Date 1,801,948 Boykow Apr. 21, 1931 2,112,965 Koster Apr. 5, 1938 2,191,250 Fischel Feb. 20, 1940 2,233,307 Dodson Feb. 25, 1941 2,423,336 Moseley July 1, 1947 2,432,166 Mallory Dec. 9, 1947 2,445,389 Chandler July 20, 1948 2,471,821 Kutzler May 31, 1949 2,496,294 Kellogg Feb. 7, 1950 

